1. Field of the Invention
The present invention relates to an illumination axis adjusting apparatus for headlamps of vehicles such as automobiles.
2. Description of the Related Art
In conventional headlamps of vehicles such as automobiles, in order to enable the vertical or horizontal adjustment of the illuminating direction thereof members for determining the illuminating direction (for example, a reflector and a headlamp unit) are mounted in a supporting member such as a casing in such a manner as to be tiltably held thereon, and manual or automatic adjustment driving devices are provided for tilting the illumination direction determining members.
In adjusting the illuminating direction of the headlamps there are employed aiming adjustment and leveling adjustment; the former adjustment is carried out after the headlamps have been assembled to the vehicle body, before the vehicle is used or at the time of inspection (normally the manual adjustment carried out manually), and the latter adjustment is carried out every time the vertical illuminating angle changes as the load exerted to the vehicle changes due to a change in the number of people riding or pieces of luggage placed in the vehicle or to the running condition (normally the automatic adjustment employing a motor or the like).
Conventionally, an aiming adjusting device which is manually operated and a leveling adjusting device which is automatically operated are separately mounted to constitute an illumination axis adjusting apparatus, and in such an adjusting device, it is common that a small DC motor or a stepping motor (a stepper motor) is used to drive the leveling device.
FIG. 8 shows an example of a conventional automotive headlamp device in which an aiming adjusting device and a leveling adjusting device are disposed individually.
In this figure, reference numeral 1 denotes a headlamp unit which is fabricated by combining a front unit 1a and a rear unit 1b after a reflector 4 and the like are accommodated inside. Reference numeral 2 denotes an operating rod for a horizontal aiming adjusting mechanism mounted on one of left- and right-hand sides (here right-hand side) of the back of the headlamp unit. The operating rod 2 has a hexagonal portion 2a at an upper end portion and a gear 2b at a lower end portion thereof. Reference numeral 3 denotes an adjusting rod provided at a rear end portion with a gear 3b which is in mesh engagement with the gear 2b of the operating rod 2. The adjusting rod 3 is provided at a front end portion with a threaded shaft portion, not shown. Provided at a position at an upper portion of the back of the reflector 4 which is closer to one of sides thereof is a nut portion, not shown, in which the threaded shaft portion of the adjusting rod 3 is screwed, whereby the adjusting rod 3 is rotatably connected to the reflector 4.
Reference numeral 5 denotes an operating rod for a vertical aiming adjusting mechanism positioned at an upper portion of the back of the headlamp unit 1 which is closer to the other side thereof (here, on the left-hand side). The operating rod 5 is provided at an upper end portion with a hexagonal portion 5a and a gear 5b at a lower end portion thereof. Reference numeral 6 denotes an adjusting rod provided at a rear end portion thereof with a gear 6b which is in mesh engagement with the gear 5b of the operating rod 5. The adjusting rod 6 is provided at a front end portion with a threaded shaft portion 6a. Provided at a position at the upper portion of the back of the reflector 4 which is closer to the other side thereof is a nut portion 4a in which the threaded shaft portion 6a of the adjusting rod 6 is screwed, whereby the adjusting rod 6 is rotatably connected to the reflector 4.
Reference numeral 7 denotes a stepping motor for a leveling adjusting mechanism. The stepping motor 7 is mounted on the back of the headlamp unit 1 and is located at a position which is spaced away from the vertical aiming adjusting mechanism. An output shaft 8 of the stepping motor 7 is titably connected to the reflector 4 and is adapted to move back and forth when signals are inputted in the stepping motor 7.
Here, the reflector 4 is held in such a condition that the reflector 4 can tilt vertically and horizontally by the output shaft 8 for automatic adjustment, the horizontal aiming adjusting mechanism and the vertical aiming adjusting mechanism.
Consequently, when operating to rotate the operating rods 2 and 5, the adjusting rods 3 and 6 rotate, whereby the reflector 4 tilts on the output shaft 8 acting as a fulcrum to thereby perform an aiming adjustment. In addition, a leveling adjustment is performed in conjunction with the axial movement of the output shaft 8 of the stepping motor 7.
Thus, the stepping motor used itself is not provided with the aiming adjusting mechanism additionally, and therefore the separately provided aiming adjusting mechanism is used to manually adjusting the aiming of the headlamp.
Due to this construction, there are needed three output shafts for required adjustments, and space is also required which is large enough for the disposition of the three adjusting mechanisms.
In addition, as is described in JP-B-6-37154, an illumination axis adjusting apparatus is known in which an adjusting shaft is shared for use between a vertical aiming adjusting mechanism and a leveling adjusting mechanism. However, since a manual adjusting mechanism needs to be provided between a stepping motor and a reflector, the aiming adjusting mechanism cannot integrally be incorporated in the stepping motor itself, and in a case where a stepping motor is used as a driving device for leveling adjustment, since an aiming adjusting device (for vertical aiming adjustment) and a leveling adjusting device are disposed separately, there have been often caused restrictions on the layout of the devices and the other constituent components such as configurations of locations or portions where both the devices are mounted and positional requirements to avoid the interference between the devices and the other constituent members disposed on the periphery thereof.
Since the conventional illumination axis adjusting apparatus is constructed as described above, in a case where a stepping motor is used, an aiming adjusting mechanism for vertical aiming adjustment and a leveling adjusting mechanism are disposed as separate members, and this increases the space required for mounting those mechanisms. In addition, the construction increases the number of points required for fixing the mechanisms to a headlamp body, as well as the number of constituent components, which causes problems of imposing restrictions on the lay out of the increased number of constituent components and resulting in a higher cost.
The invention was made with a view to solving the problems and an object thereof is to provide an illumination axis adjusting apparatus in which simplified constituent components are used and which can reduce the costs involved.
To attain the object, according to a first aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps having a stepping motor comprising integrally an automatic angle adjusting structure for automatically adjusting the angle of the illumination axis of an automotive headlamp by driving a motor and a manual angle adjusting structure for manually adjusting the angle of the illumination axis of the automotive headlamp.
According to a second aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps comprising automatic illumination axis adjusting means having integrally an automatic angle adjusting structure for automatically adjusting the angle of the illumination axis of an automotive headlamp and a manual angle adjusting structure for manually adjusting the angle of the illumination axis of the automotive headlamp, and manual angle adjusting means for manually adjusting the angle of the illumination axis of the automotive headlamp, the automatic illumination axis adjusting means being adapted for adjusting the angle of the illumination axis in vertical directions, and the manual angle adjusting means being adapted for adjusting the angle of the illumination axis in horizontal directions.
According to a third aspect of the invention, there is provide an illumination axis adjusting apparatus for automotive headlamps comprising first automatic illumination axis adjusting means having integrally an automatic angle adjusting structure for automatically adjusting the angle of the illumination axis of an automotive headlamp in horizontal directions and a manual angle adjusting structure for manually adjusting the angle of the illumination axis of the automotive headlamp, and second automatic illumination axis adjusting means having integrally an automatic angle adjusting structure for automatically adjusting the angle of the illumination axis of the automotive headlamp in vertical directions and a manual angle adjusting structure for manually adjusting the angle of the illumination axis of the automotive headlamp.
According to a fourth aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the second or third aspect of the invention, wherein the automatic illumination axis adjusting means is constituted by a stepping motor, the stepping motor having an output shaft, the output shaft being locked to a reflector of the automotive headlamp at one end thereof and having at a central portion thereof a threaded portion for receiving an axial force through the rotation of a rotor and at the other end thereof a rotary portion adapted to be rotated by a user.
According to a fifth aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the fourth aspect of the invention, further having a sliding member in mesh engagement with the rotor to thereby move in axial directions in conjunction with the rotation of the rotor, as well as with the threaded portion provided at the central portion of the output shaft.
According to a sixth aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the fifth aspect of the invention, wherein the sliding member is formed from a resin material.
According to a seventh aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the fourth aspect of the invention, further comprising a manual rotary portion adapted to restrict the direction in which the output shaft rotates and to be rotated by the user.
According to an eighth aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the seventh aspect of the invention, wherein an output shaft accommodating and holding hole is formed in the manual rotary portion so that the output shaft is accommodated and held in the output shaft accommodating and holding hole, and wherein cross-sectional shapes of the output shaft accommodating and holding hole and a portion of the output shaft which is inserted into the hole are substantially oval, D-shaped or polygonal.
According to a ninth aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the seventh aspect of the invention, wherein the manual rotary portion is inserted and held in a hole portion opened in a housing at a position on the axis of the housing, and wherein the manual rotary portion is held with a dislocation preventing member for preventing the dislocation of the manual rotary portion from the housing.
According to a tenth aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the ninth aspect of the invention, wherein a collar-like projection is disposed at an outer circumferential portion of the manual rotary portion, and wherein the dislocation preventing member is disposed such that the collar-like projection is rotatably held between an end surface of the housing and the dislocation preventing member.
According to an eleventh aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the ninth aspect of the invention, wherein a pawl-like projection is provided on one of the dislocation preventing member and the housing, and wherein a recessed portion is formed in the other for mesh engagement with the pawl-like projection.
According to a twelfth aspect of the invention, there is provided an illumination axis adjusting apparatus for automotive headlamps as set forth in the seventh aspect of the invention, wherein a seal member formed of a resilient material is provided between the manual rotary portion and the housing.
According to a thirteenth aspect of the invention, there is provided an automotive headlamp system comprising left and right headlamps mounted on an automotive vehicle and illumination axis adjusting apparatus provided for the headlamps, respectively, wherein the illumination axis adjusting apparatus has automatic illumination axis adjusting means having integrally, in turn, an automatic angle adjusting structure for automatically adjusting the angle of the illumination axis of the headlamp in horizontal directions and a manual angle adjusting structure for manually adjusting the angle of the illumination axis of the headlamp, whereby in accordance with the number of degrees of an angle through which a steering wheel of an automotive vehicle is turned, when the steering wheel is turned rightward the illumination axis of the right-hand side headlamp is adjusted rightward, while when the steering wheel is turned leftward, the illumination axis of the left-hand side headlamp is adjusted leftward.